1) Take off pants and underwear

2) Lay on a table, on your back, with just
   your head hanging over the edge

3) Lift legs up and around until your anus
   meets your scalp

4) Have two friends yank down, hard, on
   either leg

0)  Find an appropriate place to ask this question instead
of a computer hardware forum.

1)  Google it.
http://www.google.com/search?q=Using+bittorrent

2)  Find a torrent that has what you want.

3)  Install a bittorrent client.  Don't have one?  See #1.

4)  Open a hole in your firewall/router if necessary, the
port corresponding to what your client is set to use.

5)  Download the torrent file, at which point it's either
associated with the client, will open the client
automatically, or you would manually open the client and
through it, open that torrent file as if you were opening
any document in another application.

6)  Sit back and watch it download.  End the session when
you have uploaded at least as much as you've downloaded.

Note that if in #2 through 6 above, what you want is
copyrighted by certain groups, you may eventually get a
letter in the mail from the RIAA's agent(s) demanding money
or your appearance in court, since they've been tracking MP3
torrents for a few years now and will sue indiscriminately -
grandmothers, little girls, homeless people and the dead, to
them you are just a (IP) number.

Here, briefly, is the most common procedure:

Download and install a "client" such as uTorrent.

Go to mininova.org, isohunt.com, or other such site
that provides "torrent" files.  A torrent file provides
the information required to download a file.

Find and download a torrent file for the .mp3 you want.

Double-click the torrent file.  The client will ask if you
really intended to add the torrent.  Say yes the
client will begin downloading.

Files are downloaded piecewise with many computers
providing pieces.

Some gotchas:

Documentation isn't great.

Look for files that have many "seeds," computers that
can upload the file you want.  (You will be a "leecher,"
a downloader).

Ensure that all parts of the file are available.

Once you have a part of the file you will become a
seed.  As a courtesy continue to seed after you have
completed the download.

Gary

    Why downloading MP3 using Torrent when there are tons of MP3 newsgroups
which you can download much faster?

Usenet - just use any good reader with yEnc supported, or better yet Binary
Downloader is a better way to download binary from Usenet.

BitTorrent - you can either use BitTorrent client *or* Opera (Web browser)
which supports BitTorrent.